Anti-Lock Brake System: Operation
ECU receives AC signal from each wheel sensor. The ECU computes wheel speed and determines deceleration speed of vehicle. When a wheel is about to lock-up, the signal generated from that wheel will be different from deceleration speed. This difference will be detected by the ECU. Hydraulic brake pressure is then modulated by solenoid valves for the individual brake circuits. Solenoid valves are operated individually on front wheels and as a pair for rear wheels. ABS operation will continue until ECU detects that wheel speed is decreasing at the same rate for all wheels. System will cycle 4-10 times per second.